We report the case of a patient with a case of cytomegalovirus (CMV) colitis, which presented as a flare-up of her ulcerative colitis. Standard treatment for the flare-up, which included intravenous corticosteroids, bowel rest, topical salicylates and ultimately colectomy were not effective. The patient did not improve until therapy with intravenous ganciclovir was initiated. There have been 26 previous reports of CMV colitis complicating inflammatory bowel disease (IBD). The diagnosis is not frequently entertained and, if not made, leads to a high rate of colectomy (67 percent) and mortality (33 percent). Appropriate antiviral therapy appears to eliminate these complications, thus a high index of suspicion for CMV superinfection in cases of IBD refractory to traditional therapy is warranted.